Flat film bag for use in automated filling systems

ABSTRACT

A film bag, laid flat, for use in automated filling systems has a front wall, a rear wall, side folds laid in between the front wall and the rear wall, and a reclosure consisting of a reclosure strip on the inside of the bag. The reclosure strip is disposed on the inside surface of a side fold as well as on the inside surfaces of the front wall and the rear wall, and extends all the way into a two-ply bag segment (A) formed by the front wall and the rear wall. The front wall, the rear wall, and the side fold provided with the reclosure form a four-ply bag segment whose plies are releasably connected by the reclosure strip. In contrast, the segments of the reclosure strip disposed on the front wall and the rear wall are not connected in the region of the two-ply bag segment (A).

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of European Application No. 10 197 242.0 filed Dec. 29, 2010, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a film bag, laid flat, for use in automated filling systems, having a front wall, a rear wall, side folds laid in between the front wall and the rear wall, and a reclosure consisting of a reclosure strip, on the inside of the bag. The reclosure strip consists of one or more parts and is disposed on the inside surface of a side fold as well as on the inside surfaces of the front wall and of the rear wail, which follow this, and extends all the way into a two-ply bag segment formed by the front wall and the rear wail.

2. The Prior Art

Film bags having the characteristics described are filled, at the top, in automated filling systems, and subsequently sealed by at least one head sealing seam. In this connection, high-quality, mostly airtight packagings are formed, particularly for pourable products, for example granular or palletized animal food. In order to open the packaging for the first time, a top bag segment has to be removed. In this connection, the side fold provided with the reclosure is exposed; this can be used as a resealable pour spout. A bag packaging having the characteristics described is known from International Application Publication No. WO 2004/092025 A2.

In the production of the film bags, laid flat, it is practical if the reclosure is closed, and segments of the reclosure strip that lie opposite one another are brought into engagement with one another. In this way, the film plies of the film bag lie flat on top of one another, which is advantageous for handling, transport, and stacking of the film bags, laid flat. In particular, a four-ply bag segment consisting of the front wall, the rear wall, and the side wall provided with the reclosure can be prevented from being spread open by the resilience of the reclosure strip. In an automated filling system, the film bag, laid flat, is then opened using suction devices that are applied to the front wall and the rear wall of the film bag. The process should be carried out with short cycle times. In this connection, opening of the bags does not always succeed without friction, so that incorrect filling and machine down times can occur.

The reclosure strip has engagement elements. The opening force of the reclosure can be influenced by a change in the geometry of the engagement elements as well as by the material selection. In this connection, however, it should be noted that the reclosure is not allowed to open on its own during later use, for example if the filled packaging is held upside down. A reduction of the opening force by a geometrical change in the reclosure is therefore possible only within limits. It should also be taken into consideration that the temperature has a great influence on the opening force of a reclosure. At low temperatures, the force that must be applied to open the reclosure increases. In the winter, the film bags, laid flat, are therefore stored in heated halls, in order to ensure that the reclosure elements will open properly when the film bags are opened in a filling system for the purpose of filling them.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to further develop a film bag, laid flat, having a front wall, a rear wall, side folds laid in between the front wall and the rear wall, and a reclosure consisting of a reclosure strip, on the inside of the bag, in such a manner that it can always be properly opened and filled in automated segment systems.

The object of the invention and the solution for this task is a film bag, laid flat, having a front wall, rear wall, and side fold provided with the reclosure, so as to form a four-ply bag segment whose plies are releasably connected by means of the reclosure strip. In contrast, the segments of the reclosure strip disposed on the front wall and the rear wall are not connected in the region of the two-ply bag segment. By means of partial pre-opening of the reclosure, in other words by opening of the reclosure in the region of the two-ply bag segment, which must be taken into consideration in the production of the film bag, the initial force that is required to open the reclosure can be reduced. When the front wall and the rear wall are grasped with suction tools in an automated filling system and pulled apart from one another, opening of the reclosure starts in the region of the two-ply bag segment, in other words where the reclosure strips that lie opposite one another are not engaged into one another. From there, the opening process continues over the length of the reclosure, all the way into the region of the four-ply bag segment and the side fold. In this way, the film bag, laid flat, can be properly opened and filled in the filling system, without modifications of the filling system having to be made. Tempering of the film bag, laid flat, is also not necessary. In the winter, storage of the film bags, laid flat, can take place in unheated halls. The measure according to the invention does not have any effect on the opening force of the reclosure during its later use.

The engagement of the reclosure strips can be designed in such a manner that the filled packaging does not open on its own in the region of the reclosure if one holds the packaging upside down, for example.

The reclosure strip preferably consists of one piece over its entire length, and it is practical if it has a closure profile that can engage into itself. At the outer edges of the film bag, the reclosure strip is greatly curved. Because of elastic recovery forces, the closure strip tends to spread open at the outer edges of the film bag. Because the segments of the reclosure strip disposed on the side fold are engaged with the reclosure strip disposed on each of the front wall or rear wall, the film bag maintains its flat position even in the region of the four-ply bag segment. The engagement of the reclosure segments in this region counteracts spreading-open of the bag. The flat position of the four-ply bag segment contributes to making the film bag, which lies flat, stackable and easy to handle by means of automated feed devices. Partial opening of the reclosure, restricted to the two-ply bag segment, according to the invention, does not have a detrimental effect, neither on its flat position nor on handling of the flat bag, and brings about the improvement described above, when opening the bag in a filling system.

The film bag can have outer edges reinforced by means of longitudinal sealing seams. The longitudinal sealing seams connect the side folds with the adjacent front wall or rear wall. In the region of the reclosure strip, the longitudinal sealing seams are interrupted; they end below the reclosure strip and are continued in the head region above the reclosure strip. The length of the segments of the reclosure strip disposed on the front wall and the rear wall is greater than the width of the side fold that is laid in, and can be freely selected for the remainder. It can be established in such a manner that an optimal pouring opening for the product is obtained when the filled bag packaging is opened for the first time, by removing a bag segment above the reclosure, for the purpose of removing product. The length of the reclosure strip can be dimensioned so that the segments of the reclosure strip attached on the front wall and the rear wall bridge at least one-fourth of the width of the two-ply bag segment. It is practical if the segments on the two-ply bag segment extent over a length of at least 1 cm.

The reclosure strip is disposed at a distance from an upper bag edge in the head region of the film bag. The bag surface above the reclosure strip can be provided with a weakening line for tearing the bag packaging open. According to a preferred embodiment of the invention, the front wall, the rear wall, and the side fold consist of a multi-ply film that has a sealable polyolefin layer on the inside of the bag and an imprintable outer layer made of a more rigid polymer. The more rigid polymer, in contrast to the polyolefin sealing layer, which preferably consists of a polyethylene, can be cut by a laser. According to a preferred embodiment of the invention, the weakening line therefore consists of a cut produced by laser cutting, which penetrates into the outer layer and leave the sealable polyolefin layer unharmed.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows a film bag, laid flat, for use in automated filling systems, and

FIG. 2 shows a top view onto the filling opening of the film bag, which is slightly opened for purposes of the illustration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the drawings, the film bag shown in the figures has a front wall 1, a rear wall 2, side folds 3, 3′ laid in between front wall 1 and rear wall 2, as well as a reclosure 5 consisting of a reclosure strip 4, on the inside of the bag. Reclosure strip 4 is disposed on the inside surface of a side fold 3 as well as, following this, on the inside surfaces of the front wall 1 and the rear wall 2, and extends all the way to a two-ply bag segment A formed by the front wall 1 and the rear wall 2. The film bag is pre-finished and passed to an automated filling system as a film bag, laid flat, in which system it is opened, filled with product, and subsequently sealed by placement of at least one head sealing seam. Opening of the flat film bag takes place using suction tools that are applied to the front wall and the rear wall, and pull the front wall and the rear wall apart by means of positioning movements. In this connection, reclosure 5 provided on the inside surface of the film bag is also opened completely.

The representation in FIG. 2 shows the film bag, laid flat, in its delivered state, whereby front wall 1 and rear wall 2 are opened slightly merely for purposes of illustration. It can be seen from the figure that front wall 1, rear wall 2, and side fold 3 provided with reclosure 5 form a four-ply bag segment B, the plies of which are releasably connected by reclosure strip 4. The segments of reclosure strip 4 disposed on front wall 1 and rear wall 2, on the other hand, are not connected in the region of two-ply bag segment A. The film bag is pre-finished as a film bag, laid flat. In this connection, reclosure 5 is closed in the region of four-ply bag segment B, and not engaged in two-ply bag segment A. By partial pre-opening of reclosure 5, in other words by opening reclosure 5 in two-ply bag segment A, the force required for opening can be clearly reduced. When the film bag is opened in an automated filling system, the opening process of reclosure 5 starts in the region of two-ply bag segment A, in other words where the segments of the reclosure strip that lie opposite one another are not engaged into one another. The opening process then continues over the entire length of reclosure strip 4, all the way to the region of side fold 3. Reclosure 5 can thereby be properly opened for the purpose of filling the film bag. No modifications of the filling system are necessary.

Reclosure strip 4 consists of one piece over its entire length, and it is practical if it has a closure profile that can be locked into itself.

From FIG. 1, it is evident that the film bag has outer edges 7 reinforced by longitudinal sealing seams 6. Longitudinal sealing seams 6 connect side folds 3, 3′ with adjacent front wall 1 or rear wall 2, in each instance. Longitudinal sealing seams 6 are interrupted in the region of reclosure strip 4.

The length of the segments of reclosure strip 4 disposed on front wall 1 and rear wall 2 is selected so that these segments bridge at least one-fourth of the width of the two-ply bag segment A.

According to the representation in FIG. 1, reclosure strip 4 is disposed at a distance from an upper bag edge 8 in the head region of the bag. The bag surface above reclosure strip 4 is provided with a weakening line 9 for tearing the bag packaging open. Front wall 1, rear wall 2, and side folds 3, 3′ preferably consist of a multi-ply film that has a sealable polyolefin layer on the inside of the bag and an imprintable outer layer made of a more rigid polymer. Weakening line 9 can particularly consist of a cut produced by laser cutting, which penetrates into the outer layer and leaves the sealable polyolefin layer unharmed.

Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

1. A film bag for use in automated filling systems, comprising: a front wall; a rear wall; side folds laid in between the front wall and the rear wall, and a reclosure consisting of a reclosure strip, on an inside of the bag, wherein the reclosure strip is disposed on an inside surface of a side fold as well as on inside surfaces of the front wall and the rear wall, and extends all the way into a two-ply bag segment formed by the front wall and the rear wall, wherein the front wall, the rear wall, and the side fold provided with the reclosure form a four-ply bag segment whose plies are releasably connected by the reclosure strip, and wherein segments of the reclosure strip disposed on the front wall and the rear wall are not connected in a region of the two-ply bag segment.
 2. The film bag according to claim 1, wherein the reclosure strip consists of one piece over its entire length.
 3. The film bag according to claim 1, wherein the reclosure strip has a closure profile that can lock into itself.
 4. The film bag according to claim 1, wherein the film bag has outer edges reinforced by longitudinal sealing seams that connect each of the side folds with an adjacent one of front wall or rear wall, and are interrupted in the region of the reclosure strip.
 5. The film bag according to claim 1, wherein a length of the segments of the reclosure strip disposed on the front wall and the rear wall is selected so that said segments bridge at least one-fourth of a width of the two-ply bag segment.
 6. The film bag according to claim 1, wherein a length of the segments of the reclosure strip disposed on the front wall and the rear wall is selected so that said segments extend over a length of at least 1 cm on the two-ply bag segment.
 7. The film bag according to claim 1, wherein the reclosure strip is disposed at a distance from an upper bag edge and wherein a bag surface above the reclosure strip is provided with a weakening line for tearing the bag open.
 8. The film bag according to claim 7, wherein the front wall, the rear wall, and the side folds consist of a multi-ply film that has an inner sealable polyolefin layer and an imprintable outer layer made of a more rigid polymer, and wherein the weakening line consists of a cut produced by laser cutting, which penetrates into the outer layer and leaves the sealable polyolefin layer unharmed. 